The use of ultrasound for obtaining pharmaceutical grade sodium chloride

Abstract

The use of ultrasound (US) in the preparation of pharmaceutical grade (PG) sodium chloride by the sampling of final product from a vacuum evaporator during the process of obtaining the “Extra” class table salt at the crystallization stage of the sodium chloride has been investigated. The US had been used: 1) for the content control of the base matter – sodium chloride in the stock – natural brine (sonoluminescent spectroscopy method). It is necessary to create the appropriate crystallization conditions by the control of the vacuum evaporator parameters – temperature and pressure; 2) at the crystallization stage of the sodium chloride to reduce the co-crystallization between the sodium chloride and the sulfate ions. It has been shown that the use of US allows reducing the sulfate ions content in the final product and getting sodium chloride PG satisfying the requirements of pharmacopoeia standard (PS) 42-2572-88.